DENVER (AP) - A bipartisan group of 19 Western governors said Interior Secretary Ryan Zinke did not consult with them about major plans for reorganizing the agency, and have asked him to delay implementing the proposal until he speaks with them.

The Feb. 1 letter from the Western Governors Association said the group had asked Zinke in April 2017 to be consulted on any reshuffling of the department, which wields considerable authority over public lands in the West.

They said last week that Zinke has still not sought the views of its members, who represent every state in the western half of the nation, from Texas to Hawaii.

Zinke, who was a Republican congressman from Montana, said last month he wants to reorganize the department's regions along river basins and other natural boundaries instead of state lines. The plan also calls for all of the department's component agencies, such as the National Park Service and Fish and Wildlife Service, to use the same set of regional boundaries.

Association spokesman Joe Rassenfoss said Thursday the group had not received a response from Zinke.

Interior Department spokeswoman Heather Swift said the governors "are welcome to share their ideas and opinions with the secretary or their staff are also encouraged to reach out to the secretary's staff."

That did not satisfy the association.

"Western governors expect to be treated as the chief executives of a sovereign level of government, not as stakeholders," Jim Ogsbury, executive director of the group, said Thursday in an email to The Associated Press. He said the governors want to be "authentic partners" in the process.

Zinke told the Washington Post last month that many issues the Interior Department deals with, such as a single species of fish, follow natural boundaries, not political ones.

The Interior Department oversees nearly 700,000 square miles (more than 1.8 million square kilometers) through four of its major component agencies: the Bureau of Land Management, Fish and Wildlife Service, National Park Service and Bureau of Reclamation.

The Bureau of Indian Affairs, which is also part of the Interior Department, has some responsibilities for another 103,000 square miles (about 265,000 square kilometers) of Native American land.

The Western Governors Association sent Zinke 10 questions about the reorganization plan, including why the changes were even necessary, and why all the department's units couldn't have the same regions based on state boundaries.

The governors pointed out that under Zinke's plan, some states would be divided among two or three of the new regions. They asked how that would affect the department's ability to coordinate with states.

The association's letter was signed by its chairman, South Dakota Republican Gov. Dennis Daugaard, and its vice chairman, Hawaii Democrat David Ige. The association includes 12 GOP governors, six Democrats and one independent.